Only try to guess where VML is installed if a site.cfg file does exist.
Only try to guess where VML is installed if a site.cfg file does exist.

pombredanne/numexpr,andreabedini/numexpr,pombredanne/numexpr,robbmcleod/numexpr,robbmcleod/numexpr,pydata/numexpr,robbmcleod/numexpr,pydata/numexpr,andreabedini/numexpr,pombredanne/numexpr,andreabedini/numexpr,pydata/numexpr